Wireless Sensor Platform for Dry Spent Fuel Cask Monitoring

Reactor cores in commercial power plants produce spent nuclear fuel discharged every 3-4 years. There is currently a pressing need to safely store spent fuel for long periods (decades to centuries) using dry storage systems. Long duration storage requires comprehensive monitoring to ensure safe conditions as the waste decays. The system must meet challenging requirements: operate at 200 °C, withstand high radiation, have a long term power source, and communicate the walls of a sealed steel and concrete cask. Statement of How this Problem or Situation is Being Addressed RMD will investigate the design of a system that meets the requirements. By investigating the integration of a rad hard radiation sensor, self-sustaining thermoelectric power supply, and a means for transmitting data through the steel and concrete walls of sealed waste storage casks. To achieve this, RMD will collaborate with researchers at Savanah River National Laboratory, the University of Tennessee in Knoxville, and Areva Transnuclear Inc. What is to be done in Phase I: Phase I will 1) design and model the self-powered wireless cask monitor system, 2) design and implement a prototype thermoelectric generator, 3) fabricate diamond 85Kr radiation sensors, 4) develop a design for integrating the sensor and the wireless communications technology, 5) analyze the requirements of the electronic circuitry needed to power the internal devices and prepare a preliminary design, and 6) prepare a design of a complete long-term in situ cask monitoring system. Commercial Application and Other Benefits: The principal customer for our cask monitoring system is the Department of Energy and its counterparts around the world who need a rad-hard sensor to detect beta particles in nuclear fuel storage casks. According to Oak Ridge National laboratory the number of storage casks in the U.S. is growing at a rate of approximately 200 per year. On a world-wide basis, the annual discharge of fuel assemblies from the world's nuclear reactors is estimated to be 10,500 MTU. The world-wide cumulative quantity of generated spent fuel is expected to be more than 445,000 tHM by the end of 2020, with the U.S. contributing 88,000 MTU. Based on these growth rates, we estimate that there is an annual need for approximately 1,000 dry cask storage systems on a worldwide basis. We estimate that a complete system that will meet DOE’s specifications will cost approximately $40,000. Therefore, the U.S. market is approximately $8 million and we estimate the worldwide market to be valued at $40 million annually. Key Words: Nuclear waste storage cask, diamond radiation detector, wireless communication, magnetic coupling, thermoelectric generator, safeguards.